Perhaps not an answer that fits your criteria, but I have been using FreeNAS for several years now. My configuration was simple - SMB with a few jails running G

Perhaps not an answer that fits your criteria, but I have been using FreeNAS for several years now. My configuration was simple - SMB with a few jails running Gitea and Syncthing (and other misc self-hosted things off and on). Haven't had to touch the config in years -- only tinkering was for the sake of tinkering, not maintaining. So I got started when I only wanted to tinker and experiment. Bought an old Core2Duo motherboard and put 8GB DDR2 RAM on it. 2 3TB hard drives plus an old laptop hard drive for the FreeNAS install. ZFS mirror. Few years later the motherboard stopped working (not sure the problem, all capacitors seemed fine by my multimeter). Data recovery was relatively easy. I have a SATA->USB converter meant for smaller laptop hard drives. I connected one of the desktop hard drives to it by a SATA cable with the plastic on one end cut away to expose the pins (to turn it from female to male) and fit it in the USB converter and the unmolested end to the HD. Powered the HD from my power supply with a normal SATA power cable. Hooked it up to my laptop (with ZFS on it, of course) and bam! Was able to recover files. I didn't touch the setup for a while, but finally I bought an older Supermicro motherboard for its inexpense and ECC compatibility, got 2 CPUs to place, some ECC, and connected the original hard drives to it. Nearly plug-and-play. FreeNAS was able to resume from where I left off when the previous motherboard died. Updated to latest (as it had been a couple years!) and didn't have to fiddle with the config. Maybe not power efficient like you were asking, but I'm happy with it. That's my NAS "war story" -- a mild one, anyway.